diff --git a/src/Integrations/Divi/Pages/DiviComposition.php b/src/Integrations/Divi/Pages/DiviComposition.php
index e09145c..ed38b06 100644
--- a/src/Integrations/Divi/Pages/DiviComposition.php
+++ b/src/Integrations/Divi/Pages/DiviComposition.php
@@ -7,6 +7,7 @@ namespace LIT\MCP\Integrations\Divi\Pages;
 use LIT\MCP\Integrations\Divi\Compose\AttrWriter;
 use LIT\MCP\Integrations\Divi\Compose\Composer;
 use LIT\MCP\Integrations\Divi\Compose\LinkTargets;
+use LIT\MCP\Integrations\Divi\Compose\LoopScope;
 use LIT\MCP\Integrations\Divi\Compose\MediaResolver;
 use LIT\MCP\Integrations\Divi\Compose\Placeholders;
 use LIT\MCP\Integrations\Divi\Compose\ShortformWriter;
@@ -27,10 +28,11 @@ defined('ABSPATH') || exit;
 
 /**
  * Wires the pure Compose classes with the live catalog, design system, Divi's dynamic content
- * registry and the WordPress sanitizer/media lookup – once per request and entry. Ruling S31:
- * ONE VariableRef (carrying the live dynamic content map of the entry, S22), ONE Placeholders
- * and ONE ValueCleaner instance are shared by AttrWriter, ShortformWriter and Composer, and the
- * same AttrWriter serves Composer and the abilities.
+ * registry and the WordPress sanitizer/media lookup – once per request, entry and loop scope. Ruling S31
+ * (as reworded by X3): ONE VariableRef per composition (carrying the live dynamic content map of the entry, S22,
+ * plus the loop options of its LoopScope), ONE Placeholders and ONE ValueCleaner instance are shared by
+ * AttrWriter, ShortformWriter and Composer, and the same AttrWriter serves Composer and the abilities. A tool
+ * whose nodes sit in several loop scopes uses one composition – and so one Composer – per scope (inLoop()).
  *
  * Presets (D7) reach blocks through ONE PresetAssignment per composition: its book is Divi's stored preset
  * inventory (DesignSystemWriter::presets()), read lazily and at most once – only when a write names a preset or a
@@ -38,8 +40,9 @@ defined('ABSPATH') || exit;
  * Without a preset source (null, unit tests) there are no presets.
  *
  * forPost() binds the composition to the entry being written (DiviWriter::composition() does it
- * for the abilities); unbound, VariableRef's default map applies. Not final so abilities can be
- * tested with a mock.
+ * for the abilities); unbound, VariableRef's default map applies. inLoop() binds it to the loop scope of the
+ * nodes it composes (LoopContext); without it the scope is none and every loop_* option is refused. Not final so
+ * abilities can be tested with a mock.
  */
 class DiviComposition
 {
@@ -51,6 +54,10 @@ class DiviComposition
     private ?AttrWriter $attrWriter = null;
     private ?Composer $composer = null;
     private ?PresetAssignment $assignment = null;
+    private LoopScope $loop;
+
+    /** @var array<string, array<string, string>>|null Loop options of $loop for the entry (read once). */
+    private ?array $loopFields = null;
 
     public function __construct(
         private DiviModules $modules,
@@ -61,35 +68,40 @@ class DiviComposition
         private LinkTargets $links = new WpLinkTargets(),
         private ?DesignSystemWriter $presetSource = null
     ) {
+        $this->loop = LoopScope::none();
     }
 
     /** A fresh composition for entry $postId (own VariableRef with its live map; TB area for StructureRules). */
     public function forPost(int $postId, ?string $themeBuilderArea = null): static
     {
-        $bound = clone $this;
+        $bound = $this->fresh();
         $bound->postId = $postId;
         $bound->themeBuilderArea = $themeBuilderArea;
-        $bound->references = null;
-        $bound->placeholders = null;
-        $bound->cleaner = null;
-        $bound->attrWriter = null;
-        $bound->composer = null;
-        $bound->assignment = null;
 
         return $bound;
     }
 
     /**
-     * The one checker of $variable(…)$ values of this composition, with the entry's live map (S22, S31).
+     * A fresh composition of the same entry for nodes inside $scope (ruling X3): its VariableRef and Placeholders
+     * know the loop options of that kind; the abilities take $scope from LoopContext.
+     */
+    public function inLoop(LoopScope $scope): static
+    {
+        $bound = $this->fresh();
+        $bound->loop = $scope;
+
+        return $bound;
+    }
+
+    /**
+     * The one checker of $variable(…)$ values of this composition: the entry's live map (S22, S31) plus the loop
+     * options of its scope, and the scope itself for the loop messages (X5).
      *
      * @internal Public for tests; code uses cleaner() / composer().
      */
     public function references(): VariableRef
     {
-        return $this->references ??= new VariableRef(
-            $this->design->read(),
-            $this->postId === null ? null : $this->dynamicContent->forPost($this->postId)
-        );
+        return $this->references ??= new VariableRef($this->design->read(), $this->dynamicContentMap(), $this->loop);
     }
 
     /**
@@ -99,7 +111,7 @@ class DiviComposition
      */
     public function placeholders(): Placeholders
     {
-        return $this->placeholders ??= new Placeholders($this->design->read(), $this->links);
+        return $this->placeholders ??= new Placeholders($this->design->read(), $this->links, $this->loopFields());
     }
 
     /** The one choke point of this composition (ValueCleaner, rulings S1–S3, S7, S13, S28, S32). */
@@ -161,4 +173,37 @@ class DiviComposition
     {
         return new Warnings($this->design->read(), $this->presets());
     }
+
+    /** @return array<string, array<string, string>>|null The entry's live map with the scope's loop options. */
+    private function dynamicContentMap(): ?array
+    {
+        $map = $this->postId === null ? null : $this->dynamicContent->forPost($this->postId);
+
+        return $map === null ? null : $map + $this->loopFields();
+    }
+
+    /** @return array<string, array<string, string>> Loop options of the OWN scope's kind only ([] without). */
+    private function loopFields(): array
+    {
+        $kind = $this->loop->kind();
+
+        return $this->loopFields ??= $this->postId === null || $kind === null
+            ? []
+            : $this->dynamicContent->loopFields($kind, $this->postId);
+    }
+
+    /** A clone without any cached instance (they hang on the entry and the loop scope). */
+    private function fresh(): static
+    {
+        $bound = clone $this;
+        $bound->references = null;
+        $bound->placeholders = null;
+        $bound->cleaner = null;
+        $bound->attrWriter = null;
+        $bound->composer = null;
+        $bound->assignment = null;
+        $bound->loopFields = null;
+
+        return $bound;
+    }
 }
diff --git a/tests/Unit/Integrations/Divi/Pages/DiviCompositionTest.php b/tests/Unit/Integrations/Divi/Pages/DiviCompositionTest.php
index fad65fb..9ba86c8 100644
--- a/tests/Unit/Integrations/Divi/Pages/DiviCompositionTest.php
+++ b/tests/Unit/Integrations/Divi/Pages/DiviCompositionTest.php
@@ -9,6 +9,7 @@ use LIT\MCP\Integrations\Divi\BlockTree\Block;
 use LIT\MCP\Integrations\Divi\BlockTree\Document;
 use LIT\MCP\Integrations\Divi\BlockTree\NodeIndex;
 use LIT\MCP\Integrations\Divi\BlockTree\NodeSummary;
+use LIT\MCP\Integrations\Divi\Compose\LoopScope;
 use LIT\MCP\Integrations\Divi\Compose\StoredNodeGuard;
 use LIT\MCP\Integrations\Divi\Compose\TreeEditor;
 use LIT\MCP\Integrations\Divi\Compose\VariableRef;
@@ -265,4 +266,46 @@ final class DiviCompositionTest extends TestCase
         self::assertCount(1, $covering);
         self::assertStringContainsString('„CTA primär“', $covering[0]);
     }
+
+    /**
+     * Ruling X3: inLoop() gives a fresh composition bound to a loop scope – placeholders and references of the
+     * entry's map plus the loop options of that kind; outside a loop and in another kind loop content fails.
+     */
+    public function testInLoopChecksLoopContentAgainstItsScope(): void
+    {
+        $post = $this->composition()->forPost(7);
+        $inPostLoop = $post->inLoop(LoopScope::ofQueryType('post_types'));
+        $compose = static fn (DiviComposition $composition, string $content = '{{loop:post_title}}'): array => $composition
+            ->composer()->compose(
+                [['type' => 'text', 'content' => $content]],
+                Block::create('divi/column'),
+                'nodes'
+            );
+
+        $inside = $compose($inPostLoop);
+        self::assertSame([], $inside['errors']);
+        self::assertSame(
+            VariableRef::serialize('content', 'loop_post_title', ['before' => '', 'after' => '']),
+            AttrMap::desktop($inside['blocks'][0]->attrs(), 'content.innerContent')
+        );
+
+        // Placeholders get the loop fields: the short form carries before/after; outside a loop it is refused.
+        $date = $compose($inPostLoop, '{{loop:post_date}}');
+        self::assertSame([], $date['errors']);
+        self::assertStringContainsString(
+            'loop_post_date',
+            (string) AttrMap::desktop($date['blocks'][0]->attrs(), 'content.innerContent')
+        );
+        self::assertStringContainsString('braucht eine Divi-Schleife', implode(' ', $compose($post, '{{loop:post_date}}')['errors']));
+
+        self::assertStringContainsString('braucht eine Divi-Schleife', implode(' ', $compose($post)['errors']));
+        self::assertStringContainsString(
+            'passt nicht zur Schleife dieses Elements (Typ: Terme)',
+            implode(' ', $compose($post->inLoop(LoopScope::ofQueryType('post_taxonomies')))['errors'])
+        );
+
+        self::assertNotSame($post->references(), $inPostLoop->references());
+        self::assertNotSame($post->placeholders(), $inPostLoop->placeholders());
+        self::assertSame($inPostLoop->references(), $inPostLoop->references(), 'one VariableRef per scope');
+    }
 }